Method for improving adsorption of a drug from ethylene oxide derivative

ABSTRACT

The present invention relates to a method for improving adsorption on the gastrointestinal mucous layers of one or more selected from polyethylene glycol, polyethylene oxide, and polyoxyethylene polypropylene copolymer wherein the average number of repeating oxyethylene units of one ethylene oxide chain length is 17 or greater. It is possible to enhance pharmacological effects by using the present invention with drugs that have anti- H. pylori  activity.

FIELD OF THE INVENTION

The present invention relates to a method for improving adsorption of adrug on the gastrointestinal mucous layers characterized inadministration of a specific ethylene oxide derivative as the activeingredient for improving adsorption of a drug. Specifically, it relatesto a method for improving adsorption of a drug on the gastrointestinalmucous layers characterized in administration as the active ingredientfor improving adsorption of a drug one or more selected frompolyethylene glycol, polyethylene oxide, and polyoxyethylenepolypropylene copolymer where the average number of repeatingoxyethylene units of one ethylene oxide chain length is 17 or greater.

PRIOR ART

The existence of H. pylori was ascertained from the stomach tissues ofgastritis patients and since that time, H. pylori has been shown toparticipate in the morbid state of stomach and duodenal disorders,including gastritis and peptic ulcer. There have been reports of theprevention of recurrence of ulcer associated with H. pylori, and theimportance of the eradication of H. pylori is now recognized. It hasfurther been suggested that there is a cause-effect correlation betweenthe occurrence of stomach cancer and H. pylori infection, even in theabsence of carcinogens ([non-patent reference 1]).

Triple eradication therapy with antibiotics (amoxicillin andclarithromycin) and a proton pump inhibitor (lansoprazole) is currentlythe H. pylori eradication method of first choice. This is because acidstability of the drug is poor with singular use or concomitant use oftwo antibiotics due to the fact that the active optimum pH ofantibiotics is generally near neutrality, and because the highesteradication rate has thus far been obtained by concomitant use of threedrugs. Nevertheless, the eradication rate when 750 mg amoxicillin, 400mg clarithromycin, and 30 mg lansoprazole are administered twice/day forone week is only 85 to 90%. Furthermore, a novel H. pylori eradicationtherapy is needed because of problems including diarrhea, development ofresistant bacteria, varied doses, and reduced compliance that isattributed to the complexity of long-term treatment.

The use of 2-(2-trans-nonenyl)-3-methyl-4(1H)-quinolone derivatives(hereafter 1-hydroxy-2-(2-trans-nonenyl)-3-methyl-4(1H)-quinolone isreferred to as compound A) alone or in combination with otherantibiotics, and the like, and a reduction in the number of livebacteria in vivo when this compound was used alone on H. pylori infectedanimal models (Mongolian gerbils) are recited in [patent reference 1].Nevertheless, when the use of this compound alone is considered, furtheraugmentation of anti-H. pylori activity is necessary and a drug deliverytechnology with which compound A is made to effectively act against H.pylori is needed to accomplish this purpose.

H. pylori lives in the gastric mucus and surface layer of the gastricmucous membrane epithelial cells and in the spaces in between([non-patent reference 2]) and therefore, it is necessary to breakthrough the barrier effect of the mucous layers by some type of means,such as promoting adsorption of the drug on the mucous layers orimproving retention, so that the drug will act directly against the H.pylori.

On the other hand, the ethylene oxide derivatives that are used as abase for formulation, such as polyethylene glycol, polyethylene oxide,and polyoxyethylene polypropylene copolymer, are employed assolubilizing agents, plasticizers, dispersants, and stabilizers.Polyethylene glycol is used, for instance, as a stabilizer ofpolypeptides, a plasticizer of sucralfate-containing compositions, and abase for retention [of a drug] in the blood. For instance, polyethyleneoxide is used as a base for controlling dissolution and polyoxyethylenepolypropylene copolymer, for example, Pluronic, is used as a surfactant,solubilizer, emulsifier, dispersant, and the like.

As described above, various ethylene oxide derivatives are used as basesfor formulation. However, no attempts have thus far been made inconnection with technology for augmenting drug activity to use ethyleneoxide derivatives in order to augment adsorption of a drug on thegastrointestinal mucous layers where H. pylori live in order to improveadsorption of a drug on the gastrointenstinal mucous layers, and inparticular, in order to augment anti-H. pylori activity.

Consequently, the purpose of the present invention is to provide amethod of improving adsorption of a drug on the gastrointestinal mucouslayers from a specific ethylene oxide derivative.

[Patent reference] U.S. Pat. No. 6,184,230

[Non-patent reference 1] T. Watanabe et al., Gastroenterol., 115;642-648 (1998)

[Non-patent reference 2] Y. Akiyama et al., Drug Delivery System, 15-3;185-192 (2000)

DISCLOSURE OF THE INVENTION

As a result of performing intense studies under these circumstances, theinventors found that adsorption of a drug of compound A on thegastrointestinal mucous layers is high in the presence of an ethyleneoxide derivative. As a result of further studies, the inventorssuccessfully completed the present invention upon discovering thatanti-H. pylori activity in particular is augmented when the averagenumber of repeating oxyethylene units in the ethylene oxide derivativesis greater than 17.

That is, the present invention relates to

1. a method for improving adsorption of a drug on the gastrointestinalmucous layers, characterized in that one or more selected frompolyethylene glycol, polyethylene oxide, and polyoxyethylenepolypropylene copolymer where the average number of repeatingoxyethylene units of one ethylene oxide chain length is 17 or greater isadministered as the active ingredient for improving adsorption of adrug;

2. the method for improving adsorption of a drug on the gastrointestinalmucous layers according to above-mentioned 1, wherein the drug is anantibiotic;

3. the method for improving adsorption of a drug on the gastrointestinalmucous layers according to above-mentioned 2, whereby the drug hasanti-H. pylori activity;

4. a pharmaceutical composition for improving adsorption of a drug onthe gastrointestinal mucous layers, which contains at least a drug andone or more selected from polyethylene glycol, polyethylene oxide, andpolyoxyethylene polypropylene copolymer where the average number ofrepeating oxyethylene units of one ethylene oxide chain length is 17 orgreater;

5. the pharmaceutical composition for improving adsorption of a drug onthe gastrointestinal mucous layers according to above-mentioned 4, wherethe drug is an antibiotic;

6. the pharmaceutical composition according to above-mentioned 5,wherein the drug has anti-H. pylori activity;

7. the pharmaceutical composition according to above-mentioned 4,wherein the ratio of the components of the composition when theadministration form is a liquid is 0.00005% to 50% of drug and 0.1% to37.5% of ethylene oxide derivative per total composition and/or 0.1 mgto 1 g of drug and 2 mg to 1 g of ethylene oxide derivative; and

8. the pharmaceutical composition according to above-mentioned 4,wherein the ratio of the components of the composition when theadministration form is a solid is 0.01% to 95% of drug and 5% to 99.99%of ethylene oxide derivative per total composition and/or 0.1 mg to 1 gof drug and 50 mg to 1 g of ethylene oxide derivative.

As cited in the present invention, “gastrointestinal mucus” means theadhesive secretion that is secreted from the gastrointestinal mucousmembrane, for instance, the mucus at the stomach walls.“Gastrointestinal mucous layers” refers to the layers of theabove-mentioned gastrointestinal mucus that are formed on the surface ofthe gastrointestinal epithelial cells. As also cited in the presentinvention, “adsorption of a drug on the gastrointestinal mucous layers”means in vitro adsorption of a drug on the gastrointestinal mucuscomponents, reflecting in vivo adsorption of the drug. For instance, itis possible to bring a lipid (oil phase) that is a component ofgastrointestinal mucus and a drug suspension (aqueous phase) intocontact with one another and then evaluate adsorption by determining therate of adsorption of the drug on the lipid (refer to W. L. Agneta etal., Pharm. Res., 15; 66-71 (1998) on mucous layer composition). Itappears that when adsorption is improved, “retention” in thegastrointestinal mucous layer is also improved, and there are cases inthe present invention where “retention” is synonymous with adsorption.It is assumed that the ability of a drug to move to the mucous layersalso improves with improvement of adsorption of a drug on the mucouslayers. For convenience, “improvement of adsorption on the mucouslayers” means that, for instance, the rate of adsorption of a drug onthe oil phase when ethylene oxide derivative has been added to theaqueous phase is significantly increased in comparison to when ethyleneoxide derivative is not added.

As cited in the present invention, “ethylene oxide derivatives” aresubstances containing ethylene oxide chains in the molecules thereof,and examples are polyethylene glycol, polyethylene oxides, andpolyoxyethylene polypropylene copolymer. Of these, polyethylene glycol6000 (brand name Macrogol 6000, average relative molecular weight(hereafter average molecular weight) of 8000) or polyethylene glycol20000 (brand name Macrogol 20000, average molecular weight of 20000),polyethylene oxides (average molecular weight of 900,000 or 7,000,000),and polyoxyethylene polypropylene copolymer (brand name, Pluronic F68,Asahi Denka) are examples.

Moreover, as cited in the present invention, the “average number ofrepeating oxyethylene units of one ethylene oxide chain length” meansthe number of repeating oxyethylene units per one ethylene oxide chainwithin a molecule as conveniently calculated. Specifically, this isfound by calculating the value obtained by dividing the number ofrepeating oxyethylene units of all ethylene oxide chains contained inone molecule by the structural number of ethylene oxide chains. The“structural number of ethylene oxide chains” means the number ofethylene oxide chains anywhere in the structure. For example, “theaverage number of repeating oxyethylene units of one ethylene oxidechain length” can be calculated as follows:

It is clear from the schematic drawing in Table 4 that there is oneethylene oxide chain in the chemical structure of Macrogol 6000.Consequently, the total number of repeating oxyethylene units (n) ofethylene oxide chains per molecule shown in Table 3 itself becomes “theaverage number of repeating oxyethylene units of one ethylene oxidechain length (m).” That is, the “average number of repeating oxyethyleneunits of one ethylene oxide chain length” of Macrogol 400, Macrogol4000, Macrogol 6000, and Macrogol 20,000 is 8, 72, 188, and 455,respectively. Moreover, Pluronic has two ethylene oxide chains in itsstructure (Table 4) and therefore, the value obtained by dividing thetotal number of repeating oxyethylene units of ethylene oxide chains permolecule (n, Table 3) by two is “the average number of repeatingoxyethylene units of one ethylene oxide chain length.” That is, thetotal number of repeating oxyethylene units of ethylene oxide chainsmolecules of L31, L44, L64, P103, P85, and F68 is 3, 20, 27, 29, 54, and160, respectively; therefore, the “average number of repeatingoxyethylene units of one ethylene oxide chain length” becomes 1.5, 10,13.5, 14.5, 27, and 80, respectively.

Adsorption of a drug on the gastrointestinal mucous layers is improvedwhen the “average number of repeating oxyethylene units of one ethyleneoxide chain length” is 17 or greater, preferably 27 or greater.

By means of the present invention, adsorptivity of compound A and2-(2-trans-nonenyl)-3-methyl-4(1H)quinolone derivatives on thegastrointestinal mucous layers is improved. Examples of these otherdrugs are pharmaceutically acceptable antibiotics, includingnitroimidazole antibiotics, specifically tinidazole and metronidazole;tetracyclines, specifically tetracycline, minocycline, and doxycycline;penicillins, specifically amoxicillin, ampicillin, talampicillin,bacampicillin, lenampicillin, mezlocillin, and sultamicillin;cephalosporins, specifically cefaclor, cefadroxil, cephalexin,cefpodoxime proxetil, cefixime, cefdinir, ceftibuten, cefotiam hexetil,cefetamet pivoxil, and cefuroxime axetel; penems, specifically,faropenem and ritipenem acoxil; macrolides, specifically erythromycin,oleandomycin, josamycin, midecamycin, rokitamycin, clarithromycin,roxithromycin, and azithromycin; lincomycins (for instance, lincomycinand clindamycin); aminoglycosides, specifically, paromomycin; andquinolones, specifically ofloxacin, levofloxacin, norfloxacin, enoxacin,ciprofloxacin, lomefloxacin, tosufloxacin, fleroxacin, sparfloxacin,temafloxacin, nadifloxacin, grepafloxacin, and pazfloxacin, as well asnitrofurantoin, and the like. Other examples are pharmaceuticalcompounds that are used to treat disease associated with stomach acidsecretion, and the like, such as acid pump inhibitors, specificallyomeprazole and lansoprazole; and H2 antagonists, specifically,ranitidine, cimetidine, and famotidine. Further examples include drugsused to treat hyponatremia, specifically4′-[2-methyl-1,4,5,6-tetrahydroimidazo[4,5-d][1]benzazepin-6-yl]carbonyl]-2-phenylbenzanilidehydrochloride; and antigastrin drugs, specifically(R)-1-[2,3-dihydro-1-(2′-methylphenacyl)-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl]-3-(3-methylphenyl)urea,pirenzepine hydrochloride, secretin, and proglumide. One of these drugsor a combination of two or more of these drugs can be used.

There are no special restrictions to the amount of drug used in thepresent invention as long as it is the amount that is effective in termsof treating disease.

It is difficult to unconditionally specify the ratio of each componentwhen they are made into a composition. For instance, when theadministration form is a liquid, such as a suspension, there is 0.00005%to 50%, preferably 0.00015% to 0.25%, particularly 0.0003% to 0.15%, ofdrug per entire composition. Moreover, there is 0.1% to 37.5%,preferably 0.1% to 25%, of ethylene oxide derivative per entirecomposition. When the administration form is a solid, such as a powder,it is possible to bring the amount of drug per entire composition to0.01% to 95%, preferably 0.1% to 90%, of drug per entire composition,and to bring the amount of ethylene oxide derivative per entirecomposition to 5% to 99.99%, preferably 10% to 99.9%.

When the administration form is a liquid, it is possible to bring theamount of drug per entire composition to 0.00005% to 50%, preferably0.0001% to 30%, and to bring the amount of ethylene oxide derivative perentire composition to 0.1% to 37.5%, preferably 1% to 25%.

There is a chance that sufficient adsorption of a drug will not beobtained if the ethylene oxide composition ratio is lower than thatcited here.

With regard to the amount of each component that is used, when theadministration form is a liquid, for instance, the amount of drug isbrought to 1 mg to 1 g, preferably 0.5 mg to 750 mg, and the amount ofethylene oxide derivative is brought to 2 mg to 1 g, preferably 5 mg to750 mg.

When the administration form is a solid, for instance, the amount ofdrug is brought to 0.1 mg to 1 g, preferably 0.5 mg to 750 mg, and theamount of ethylene oxide derivative is brought to 50 mg to 1 g,preferably 50 mg to 750 mg.

As with the composition ratio, there is a chance that sufficientadsorption of a drug will not be realized if the amount used is lessthan that cited here.

The ethylene oxide derivative of the present invention can be made intoa pharmaceutical composition for oral use together with a drug and anappropriate filler and the like that are generally acceptedpharmaceutically. There are no special restrictions to the form of thepharmaceutical preparation that this pharmaceutical composition for oraluse can take, and a form that can be orally administered, includingpowders, tablets, capsules, liquids, suspensions, and emulsions, can becited as an example. Formulation can be manufactured by a conventionalproduction method.

Excipients, such as fillers, disintegrators, binders, lubricants,fluidizing agents, dispersants, suspending agents, emulsifiers,preservatives, and stabilizers, can be included in the “filler and thelike that are generally accepted pharmaceutically” as cited in thepresent invention.

Examples of fillers are lactose, mannitol, potato starch, wheat starch,rice starch, corn starch, and crystalline cellulose; examples ofdisintegrators are sodium bicarbonate and sodium lauryl sulfate;examples of dispersants are crystalline cellulose, dextrin, and citricacid; examples of solubilizing agents are hydroxypropyl methylcellulose,polyoxyethylene-hydrogenated castor oil, cyclodextrins, and polysorbate80; examples of inflating agents are carboxymethyl cellulose,carboxymethyl cellulose calcium, and croscarmellose sodium; and examplesof surfactants are sodium lauryl sulfate and sucrose fatty acid ester.One or two or more can be mixed in appropriate amounts as needed.

The manufacturing method when these are made into a pharmaceuticalcomposition for oral use involves, for instance, introducing Macrogol6000 (polyethylene glycol 6000), drug (compound A), and filler and thelike as needed to a pharmaceutically acceptable medium and thoroughlymixing these until they are dissolved or suspended. Ion-exchanged water,buffer solution or physiological saline, and the like can be selected asthe pharmaceutically acceptable medium. Furthermore, this solutionand/or suspension can be filled into capsules, such as gelatin capsules,to obtain a capsule form. The method whereby Macrogol 6000, compound A,and pharmaceutical filler and the like as needed are granulated by aconventional method, such as pulverizing, spray drying, freeze drying,wet granulation, or dry granulation, can be cited as a method of makinga powder. Moreover, it is also possible to further add pharmaceuticalfiller and the like as appropriate and tablet the mixture to obtain thetablet form.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing showing drug permeability in the mucouslayers.

FIG. 2 is a graph showing the effect of the total number of ethyleneoxide (POE) repeating oxyethylene units per molecule on the rate ofadsorption of a drug on the oil phase.

FIG. 3 is a graph showing the effect of the calculated average number ofrepeating oxyethylene units per ethylene oxide (POE) chain length on therate of adsorption of a drug on the oil phase.

FIG. 4 is a graph showing the effect of surface tension on the rate ofadsorption of a drug on the oil phase.

FIG. 5 is a graph showing the effect of the ethylene oxide (POE) contenton the rate of adsorption of a drug on the oil phase.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in specific terms usingexamples, but the scope of the present invention is not limited by theseexamples.

EXAMPLE 1

A specific amount of compound A was added to ion-exchanged water and adrug suspension was obtained by exposure for 20 minutes to ultrasonicwaves (Sono Cleaner, Kaijo Corporation). The concentration ofpolyethylene glycol 6000 (Sanyo Chemical Industries, Ltd.; brand nameMacrogol 6000) added was adjusted to 0, 1.5%, 3.5%, 10%, 12%, and 35%.

Experiment 1

Compound A is a drug that acts directly from the gastric lumen side onthe H. pylori that lives in the mucous layers and therefore, the casewherein after dissolution (1), the bulk powder that has beenadministered transfers (IV) and the case where the bulk powder isdissolved (II) after transferring to the mucous layers (III) will beconsidered. The effects of Macrogol 6000 on the course of dissolution ofcompound A were studied. A specific amount of compound A was added toion-exchanged water, a 0.8% mucin (Sigma) solution, a 6.2% BSA (Sigma)solution, and linoleic acid (Sigma), and various drugs suspensions wereobtained by exposure for 20 minutes to ultrasonic waves (Sono Cleaner,Kaijo Corporation). The rest of the procedure was performed as inExample 1 and the following samples were obtained.

[Samples]

(1) Dispersion of compound A in water (compound A concentration: 530μg/mL)

(2) Dispersion of compound A in water (compound A concentration: 530μg/mL)+Macrogol 6000 (3.5%)

(3) Dispersion of compound A in aqueous mucin solution (0.8%) (compoundA concentration: 300 μg/mL)

(4) Dispersion of compound A in aqueous mucin solution (0.8%) (compoundA concentration: 300 μg/mL)+Macrogol 6000 (3.5%)

(5) Dispersion of compound A in aqueous BSA solution (6.2%)

(6) Dispersion of compound A in aqueous BSA solution (6.2%)+Macrogol6000 (3.5%)

(7) Dispersion of compound A in linoleic acid

(8) Dispersion of compound A in linoleic acid+Macrogol 6000 (10%)

[Method]

Solubility of compound A in water was calculated by filtering the liquidafter dispersion using a hydrophilic filter (0.45 μm, Advantec) andsubmitting the product to assay by high-performance liquidchromatography (HPLC hereafter) (n=2, sample (1); n=3, sample (2)).

Solubility of the drug in mucin was calculated by filtering the liquidafter dispersion using a hydrophilic filter (0.8 μm, Advantec) andsubmitting the product to assay by HPLC (n=3, samples (3) and (4)).

The liquid after dispersion was filtered with a hydrophilic filter (0.45μm, Advantec), absorbance at 370 nm and 550 nm (corrected for turbidity)was determined under room temperature using an ultraviolet-visiblespectrophotometer, and solubility was calculated (n=3, samples (5) and(6)).

The liquid after dispersion was filtered with a hydrophilic filter (0.45μm, Advantec), absorbance at 366 nm and 550 nm (corrected for turbidity)was determined under room temperature using an ultraviolet-visiblespectrophotometer, and solubility was calculated (n=3, samples (7) and(8)).

[Results and Discussion]

Even though there was not a significant increase in solubility ofcompound A when the Macrogol 6000 was increased up to 3.5% ((2), 0.1μg/mL) in comparison to the case where Macrogol 6000 was not added ((1),0.1 μg/mL), when 0.2% of Macrogol 6000 was added to compound A andadministered to H. pylori-infected animal models (Mongolian gerbils),augmentation of in vivo anti-H. pylori activity was seen (Example 4) incomparison to the case where Macrogol 6000 was not used. Therefore, itappears that the main reason for augmentation of in vivo anti-H. pyloriactivity is not improvement of drug solubility in water by the Macrogol6000. TABLE 1 Effect of PEG6000 on the solubility of chemical compound Ain water and/or components of mucus layer solvent solubility (μg/mL)distilled water   0.1 ± 0.05 {close oversize parenthesis} # +3.5%PEG6000   0.1 ± 0.04 0.8% mucin aq. solution   5.9 ± 1.7 {close oversizeparenthesis} # +3.5% PEG6000   6.9 ± 0.5 6.2% BSA aq. solution 18.0 ±4.8 {close oversize parenthesis} * +3.5% PEG6000 26.9 ± 1.9 linoleicacid 135.0 +10% PEG6000 110.0(*; p < 0.05,#; not significantly different)*: p < 0.01

The mucous layers in the digestive tract comprise water, mucin, proteinsand lipids (W. L. Agneta et al., Pharm. Res., 15; 66-71 (1998)); thus,the effects of addition of Macrogol 6000 on solubility of compound A invarious types of mucus components were investigated (Table 1).

Although solubility of compound A in aqueous mucin solution (sample (3),5.9 μg/mL) was markedly increased when compared to solubility in water,when Macrogol 6000 was added (sample (4), 6.9 μg/mL), the increase wasonly 1.2-fold. Although solubility of compound A in BSA solution as amodel of a protein that comprises the mucous layers (sample (5), 18.0μg/mL) was markedly increased when compared to solubility in water, whenMacrogol 6000 was added (sample (6), 26.9 μg/1 mL), the increase wasonly 1.5-fold. It is reported that the total amount of each lipidcomprising mucus is 37%, and the highest content of the lipidscomprising mucus is that of linoleic acid at 24% (W. L. Agneta et al.,Pharm Res., 15; 66-71 (1998)). Although solubility of compound A inlinoleic acid (sample (7), 135.0 μg/mL) was markedly increased whencompared to solubility in water, an increase was not seen when Macrogol6000 was added (sample (8), 110.0 μg/mL). Based on the above-mentionedresults, it can be assumed that once it has transferred to the mucouslayers, compound A is easily dissolved in the mucous layers at thebactericidal concentration (concentration that is 10-fold the minimumconcentration (0.025 μg/mL) at which an increase in bacteria isinhibited), but the increase in solubility of compound A in mucouscomponents when Macrogol 6000 is added (1.2-fold to 1.5-fold) ismarkedly low in comparison to the increase in the amount of compound Athat is adsorbed on the oil of the mucus components (2.0-fold, refer toExample 2), and it appears that Macrogol 6000 is not a main factor inthe augmentation of in vivo anti-H. pylori activity (refer to Example4).

According to the above-mentioned, it appears that the main reason forthe augmentation of in vivo anti-H. pylori activity is not improvementof solubility of compound A in water or mucus components due to theaddition of Macrogol 6000.

Experiment 2

[Method]

In order to study adsorption of a drug from an aqueous phase onto an oilphase (model of mucous layers), an in vitro test system wherein mixingof the oil components in the aqueous phase is prevented was constructedby immobilizing the oil phase with a gelling agent and separating itfrom the aqueous phase of a drug suspended in a mucin solution.Immobilization of the oil phase was performed by adding 120 mg of an oilgelling agent, which is a natural oil and fat fatty acid extracted fromcastor oil (Johnson Co., Ltd.), to 2 mL of medium chain fatty acidtriglyceride (Nihon Oils and Fats Co., Ltd.; brand name: Panaset) andpreparing an oil gel in a test tube (inner diameter of 1 cm, Eiken tubeNo. 5). A solution of 600 μg of compound A suspended in 2 μL of anaqueous 0.8% mucin solution was prepared and brought into contact withthe oil phase (n=6). When Macrogol 6000 was added to the aqueous phase,the concentration was brought to 3.5% (n=3 to 6). After setting thesolution aside for two hours, the aqueous phase was recovered andcompound A was assayed by HPLC. Furthermore, the surface of the oilphase was washed with methanol and compound A in the recovered solutionwas assayed by HPLC.

[Results and Discussion]

When compared to the matter adhering to the surface of the oil phasewhen the mucin solution alone or the compound A-mucin suspension wasbrought into contact with the immobilized oil phase and set aside andthen the aqueous phase was decanted, an increase in adhering matter wasobserved when Macrogol 6000 was added. When the compound A in theadhering matter was separated and assayed (Table 2), the amount of drugadsorbed at the surface of the oil phase was 259 μg (47% of the chargedamount) in the case of the compound A-mucin suspension, whereas thisincreased to 506 μg (2.0-fold) when Macrogol 6000 was added, with anaverage of 93% of the drug that was added adsorbed at the surface of theoil phase. Moreover, it was confirmed that the Macrogol 6000 aggregated,apparently as a result of interaction, in the aqueous mucin solution (nodrug added). Based on these facts, it was concluded that when thismucin-Macrogol 6000 aggregate produced by aggregation of Macrogol 6000and mucin was adsorbed by the oil, the drug was retained in theaggregate and there was an increase in the amount of drug adsorbed onthe oil phase. On the other hand, it was suggested that because therewas not an increase in the amount of drug adsorbed on the oil phase whenmucin was not added, regardless of whether or not Macrogol 6000 wasadded (Table 2), mucin and Macrogol 6000 must both be present in orderfor the amount of drug adsorbed in the oil phase to increase.

Based on the above-mentioned, it is concluded that in terms of amechanism of augmenting the in vivo anti-H. pylori activity of compoundA, the addition of Macrogol 6000 participates little in improvement ofsolubility of compound A in water or in mucus components (Table 1).Moreover, it can also be assumed that the addition of Macrogol 6000participates little in the diffusibility of drug in the mucous layersafter dissolution. Consequently, it appears that in terms of a mainfactor in augmenting the in vivo anti-H. pylori activity of compound A,compound A adsorption on mucus is improved when Macrogol 6000 aggregateswith mucin and is adsorbed by the lipids (oils) that are a component ofmucus.

Experiment 3

[Method]

The rate of adsorption of a drug of compound A on the oil phase wasmeasured by the same method as in Example 2.

[Results and Discussion]

The effect of the number of repeating oxyethylene units of ethyleneoxide (POE) on the rate of adsorption of a drug on the oil phase (Table3) was investigated. In contrast to the fact that a significant increasein the adsorption rate was seen when the number of repeating oxyethyleneunits (n) was 72 or greater when Macrogol was added, and 54 or greaterwhen Pluronic was added, increasing the number of repeating oxyethyleneunits up to 100 had no effect on the adsorption rate when hydrogenatedcastor oil (Japan Chemicals Co., Ltd., HCO) was added. When thecorrelation between the adsorption rate and the number of POE repeatingoxyethylene units is analyzed (FIG. 2), the correlation coefficient is0.4, indicating that the correlation between the two is low. TABLE 3Adsorption of chemical compound A on the oil-gel phase in presence ofvarious excipients contains of polyoxyethylene (POE) units in moleculeexcipient n m amount(%) without excipient 0 0 19 ± 7 PEG400 8 8 42 ± 94000 72 72 42 ± 4 * 6000 188 188 72 ± 3 * 20000 455 455 79 ± 0 *Pluronic L31 3 1.5 28 ± 5 L44 20 10 25 ± 2 L64 27 13.5 32 ± 5 P103 2914.5 22 ± 7 P85 54 27 40 ± 4 * F68 160 80 67 ± 3 * HCO 60 60 10 33 ± 1480 80 13.3 17 ± 10 100 100 16.7 37 ± 11*: p < 0.01

TABLE 4 Chemical structures and schematic images of PEG derivatives PEGderivative chemical structure PEG HO(C₂H₄O)_(n)H polyethylene glycolPlurronic surfactant HO(C₂H₄O)_(a)(C₃H₆O)_(c)(C₂H₄O)_(b)Hpolyoxyethylene poly- oxypropylene co-polymer HCO surfactantpolyoxyethylene stearic acid tri-glyceride

Experiment 4

[Method]

In vivo anti-H. pylori activity was evaluated with animal experimentsusing Mongolian gerbil infection models. The sample solutions were drugsolutions that have been prepared by suspension of compound A using an0.5% methylcellulose solution containing 0.2% of Macrogol 6000. The drugwas administered twice a day for three days at an administration volumeof 20 mL/kg using an oral stomach tube. The stomach was autopsied andexcised and the number of H. pylori in the stomach were measured the dayafter the final administration. In vivo anti-H. pylori activity wasevaluated from clearance, that is, the ratio of the number of cases inwhich H. pylori was identified and the number of cases in which thenumber of bacteria after treatment was below the detection limit.

[Results and Discussion]

In vivo anti-H. pylori activity was evaluated by animal experimentsusing Mongolian gerbil infection models (Table 5). The 0.5%methylcellulose suspension (MC suspension) showed clearance of 80% witha dose of 1 mg/kg. When 0.2% of Macrogol 6000 was added to the 0.5% MCsuspension, clearance was 80% or greater with a dose of 0.1 mg/kg orhigher, indicating that there was augmentation (10-fold) of the in vivoanti-H. pylori activity of compound A. The main reason for the augmentedin vivo anti-H. pylori activity of compound A appears to be that theMacrogol 6000 aggregated with the mucin so that the drug was taken upwhen the aggregate was adsorbed on the lipids (oils) that are mucuscomponents, improving mucus adsorption of compound A (refer to Table 2).

It is clear from the results in Experiments 1 through 4 that the mainfactor in the compound A in vivo anti-H. pylori activity-augmentingmechanism of Macrogol 6000 is that the Macrogol 6000 forms an aggregatewith the mucin in the mucus components so that the drug is taken up whenthis aggregate is adsorbed on the oil that is a mucus component, withthe amount of drug adsorbed in vitro on the immobilized oil phaseincreasing when Macrogol 6000 is added. The in vivo anti-H. pyloriactivity of compound A increased when Macrogol 6000 was added;therefore, it was shown that there is a correlation with an increase inthe amount of drug adsorbed on the mucus component (oil) in vitro.Furthermore, there was also a correlation between adsorption of a drugon an oil and the average number of repeating oxyethylene units of oneethylene oxide chain length, with 17 or greater being the average numberof repeating oxyethylene units of one ethylene oxide chain length withwhich there is a significant increase in adsorption of a drug on animmobilized oil phase. TABLE 5 Therapeutic efficacy of chemical compoundA against H. pylori infection in Mongolian gerbils Clearance rate(Clearance ratio) Concentration Dose (mg/kg) of PEG6000(%) 0 0.1 0.3 1 30 0%  0%  20% 80%  80% (0/5) (0/5) (1/5) (4/5) (4/5) 0.2 0% 80% 100% 80%100% (0/5) (4/5) (4/4) (4/5) (4/4)

Experiment 5

[Method]

The amount of various drugs adsorbed in vitro was measured using themethod in Example 2. A solution of 600 μg of each compound suspended in2 mL of an aqueous 0.8% mucin solution was prepared and brought intocontact with the oil phase (n=3.6). When Macrogol 6000 was added to theaqueous phase, it was brought to 3.5% (n=3.6). After setting thesolution aside for 2 hours, the aqueous phase was recovered and the drugcontent in the aqueous phase was found by assaying each compound with anultraviolet-visible spectraphotometer. The compounds that were used werenifedipin, nicardipine hydrochloride, compound B, and compound C.Compound B was(R)-1-[2,3-dihydro-1-(2′-methylphenacyl)-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl]-3-(3-methylphenyl)urea,and compound C was4′-[(2-methyl-1,4,5,6-tetrahydroimidazo[4,5-d][1]benzazepin-6-yl)carbonyl]-2-phenylbenzanilidehydrochloride. Furthermore, the oil phase surface was washed withmethanol and the drug adsorbed on the oil phase in the recoveredsolution was assayed with an ultraviolet-visible spectrophotometer foreach compound.

[Results and Discussion]

The amount of drug adsorption of each compound adsorbed on the surfaceof the oil phase when Macrogol 6000 was added increased significantly incomparison to when Macrogol 6000 was not added (Table 6). This isapparently because the drug was taken up when the aggregate of Macrogol6000 and mucin was adsorbed on the lipid (oil) that is a mucuscomponent. TABLE 6 Effect of PEG6000 on the adsorption amount of variouschemical compounds on the oil-gel phase (n = 3; mean ± SD) adsorptionamount of chemical compound(μg) chemical compound without PEG6000 with3.5% PEG6000 nifedipine 429 ± 4  506 ± 4  * nicardipine 47 ± 6 96 ± 5 *chemical compound B 269 ± 13 411 ± 3  * chemical compound C # 335 ± 10370 ± 12 *#; n = 6, mean ± SD600 μg loading*; P < 0.01

INDUSTRIAL APPLICABILITY

The present invention relates to a method of increasing adsorption of adrug on the gastrointestinal mucous layers using an ethylene oxidederivative and makes it possible to augment the in vivo anti-H. pyloriactivity of a drug by increasing adsorption of a drug ongastrointestinal mucus. Furthermore, the present invention can beapplied to singular drug eradication therapy, which has been difficultto accomplish by the current therapies for H. pylori eradication, andthis will help to improve compliance.

1. A method for improving adsorption of a drug on the gastrointestinalmucous layers, characterized in that one or more selected frompolyethylene glycol, polyethylene oxide, and polyoxyethylenepolypropylene copolymer where the average number of repeatingoxyethylene units of one ethylene oxide chain length is 17 or greater isadministered as the active ingredient for improving adsorption of adrug.
 2. The method for improving adsorption of a drug on thegastrointestinal mucous layers according to claim 1, wherein the drug isan antibiotic.
 3. The method for improving adsorption of a drug on thegastrointestinal mucous layers according to claim 2, whereby the drughas anti-H. pylori activity.